Analysis of the interaction between ground silicate aggregate and an oversupply of strong basic solution to develop a new ASR test method

First published in
RILEM bookseries  
Number in series
49
Start Page
275
End Page
282
Citation
RILEM Bookseries 49: 275-282
Contribution to Conference
17th International Conference on Alkali-Aggregate Reactions in Concrete, ICAAR 2024  
Publisher DOI
10.1007/978-3-031-59419-9_32
Scopus ID
2-s2.0-85207901274
Publisher
Springer
ISSN
22110844
The alkali-silica reaction (ASR) still causes considerable damage to concrete structures and furthermore the most beneficial method to avoid ASR is to test the aggregate for reactivity. There are internationally different but similar test methods for a reliable assessment of the damage potential of an aggregate, but these methods require specially manufactured specimens and test durations up to several months. Furthermore, a method for the short-term characterization of the aggregate is still missing. Therefore, the Institute of Materials, Physics and Chemistry of Buildings at Hamburg University of Technology (TUHH) is working on the development of a new fast test method. The idea of this new test method is an accelerated dissolution experiment. However, in this approach the time dependent change of chemical parameters due to the dissolution process in hot basic solution with an excess of alkalis is used to estimate the reactivity. The pH, the electrical conductivity, and the redox potential are recorded as a function of time. The assumption is that the different alkali reactivity of the aggregates is significantly reflected in the chemical parameters, which should make a categorization regarding the alkali reactivity possible.
Subjects
ASR
ASR testing method
dissolution experiments
electrical conductivity
reaction kinetics
DDC Class
690: Building, Construction